Net Property (Details) - USD ($) $ in Millions	Mar. 31, 2022	Sep. 30, 2021
Property, Plant and Equipment [Line Items]
Property at cost	$ 1,557	$ 1,550
Less: accumulated depreciation	(1,046)	(1,033)
Net property	511	517
Land and land improvements
Property, Plant and Equipment [Line Items]
Property at cost	42	41
Buildings
Property, Plant and Equipment [Line Items]
Property at cost	231	231
Machinery and equipment
Property, Plant and Equipment [Line Items]
Property at cost	1,055	1,051
Company-owned tooling
Property, Plant and Equipment [Line Items]
Property at cost	169	164
Construction in progress
Property, Plant and Equipment [Line Items]
Property at cost	$ 60	$ 63